This invention relates to an electric noise absorber for absorbing electric noise which is generated within an electronic device or which enters from the outside into the device through a line cord or cable.
As a method for absorbing such noise, it is well-known that ferrite can be attached to encircle a line cord or cable. In this method, two pieces of half ring-shaped ferrite are simply attached around the line cord by an adhesive tape. It is troublesome to attach the separate pieces to the line cord or cable and to detach the adhesive tape. Upon attachment of the noise absorber, the pieces are apt to easily become detached from the line cord due to an uncovered state of the ferrite and it cannot be used for an extended period of time. In addition, vibration may cause a displacement of the noise absorber from an initially-attached position to the line cord. When the ferrite is conductive, short-circuit and the like may cause within the electronic device.
To solve the above problem, a holding case for holding the one piece ferrite has been proposed and developed. Such a holding case can not open or close; it is necessary to attach the holding case before wiring. In the holding case, a case portion for holding the ferrite and a mounting portion for mounting the holding case to the electronic device are integrally constructed. In general, the electric noise is generated after completion of assembly of the electronic device. Once the wiring is rearranged, the noise absorber need to be detached and then again attached to the wire.
Furthermore, positions and numbers of the absorber must be beforehand determined on the spot. The positions and numbers of the absorbers must be determined beforehand. Therefore, the experienced technique is required. It is not easy to change the numbers of the absorbers attached and positions thereof to the cord after the electronic absorber has been assembled. In the prior art as described, the mounting portion is screwed or bolted on the electronic device. As an operation for mounting the holding case on the electronic device and an operation for setting the ferrite in the holding case clearly separated and further the mounting portion of the case projects sidewardly, a flat mounting area is required on the holding case. Also, the mounting portion projects outwardly, a large space is thus required on the holding case, and a small-sized holding case cannot be attained. Since the respective portions are integrally constructed, once the holding case is fixed on a position of the electronic device, it is not easy to rearrange it to another position.